tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Generic HDLC support routines for Linux
4 * X.25 support
5 *
6 * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
7 */
8
9#include <linux/errno.h>
10#include <linux/gfp.h>
11#include <linux/hdlc.h>
12#include <linux/if_arp.h>
13#include <linux/inetdevice.h>
14#include <linux/init.h>
15#include <linux/kernel.h>
16#include <linux/lapb.h>
17#include <linux/module.h>
18#include <linux/pkt_sched.h>
19#include <linux/poll.h>
20#include <linux/rtnetlink.h>
21#include <linux/skbuff.h>
22#include <net/x25device.h>
23
24static int x25_ioctl(struct net_device *dev, struct ifreq *ifr);
25
26/* These functions are callbacks called by LAPB layer */
27
28static void x25_connect_disconnect(struct net_device *dev, int reason, int code)
29{
30 struct sk_buff *skb;
31 unsigned char *ptr;
32
33 if ((skb = dev_alloc_skb(1)) == NULL) {
34 netdev_err(dev, "out of memory\n");
35 return;
36 }
37
38 ptr = skb_put(skb, 1);
39 *ptr = code;
40
41 skb->protocol = x25_type_trans(skb, dev);
42 netif_rx(skb);
43}
44
45
46
47static void x25_connected(struct net_device *dev, int reason)
48{
49 x25_connect_disconnect(dev, reason, X25_IFACE_CONNECT);
50}
51
52
53
54static void x25_disconnected(struct net_device *dev, int reason)
55{
56 x25_connect_disconnect(dev, reason, X25_IFACE_DISCONNECT);
57}
58
59
60
61static int x25_data_indication(struct net_device *dev, struct sk_buff *skb)
62{
63 unsigned char *ptr;
64
65 skb_push(skb, 1);
66
67 if (skb_cow(skb, 1))
68 return NET_RX_DROP;
69
70 ptr = skb->data;
71 *ptr = X25_IFACE_DATA;
72
73 skb->protocol = x25_type_trans(skb, dev);
74 return netif_rx(skb);
75}
76
77
78
79static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb)
80{
81 hdlc_device *hdlc = dev_to_hdlc(dev);
82 hdlc->xmit(skb, dev); /* Ignore return value :-( */
83}
84
85
86
87static netdev_tx_t x25_xmit(struct sk_buff *skb, struct net_device *dev)
88{
89 int result;
90
91
92 /* X.25 to LAPB */
93 switch (skb->data[0]) {
94 case X25_IFACE_DATA: /* Data to be transmitted */
95 skb_pull(skb, 1);
96 if ((result = lapb_data_request(dev, skb)) != LAPB_OK)
97 dev_kfree_skb(skb);
98 return NETDEV_TX_OK;
99
100 case X25_IFACE_CONNECT:
101 if ((result = lapb_connect_request(dev))!= LAPB_OK) {
102 if (result == LAPB_CONNECTED)
103 /* Send connect confirm. msg to level 3 */
104 x25_connected(dev, 0);
105 else
106 netdev_err(dev, "LAPB connect request failed, error code = %i\n",
107 result);
108 }
109 break;
110
111 case X25_IFACE_DISCONNECT:
112 if ((result = lapb_disconnect_request(dev)) != LAPB_OK) {
113 if (result == LAPB_NOTCONNECTED)
114 /* Send disconnect confirm. msg to level 3 */
115 x25_disconnected(dev, 0);
116 else
117 netdev_err(dev, "LAPB disconnect request failed, error code = %i\n",
118 result);
119 }
120 break;
121
122 default: /* to be defined */
123 break;
124 }
125
126 dev_kfree_skb(skb);
127 return NETDEV_TX_OK;
128}
129
130
131
132static int x25_open(struct net_device *dev)
133{
134 int result;
135 static const struct lapb_register_struct cb = {
136 .connect_confirmation = x25_connected,
137 .connect_indication = x25_connected,
138 .disconnect_confirmation = x25_disconnected,
139 .disconnect_indication = x25_disconnected,
140 .data_indication = x25_data_indication,
141 .data_transmit = x25_data_transmit,
142 };
143
144 result = lapb_register(dev, &cb);
145 if (result != LAPB_OK)
146 return result;
147 return 0;
148}
149
150
151
152static void x25_close(struct net_device *dev)
153{
154 lapb_unregister(dev);
155}
156
157
158
159static int x25_rx(struct sk_buff *skb)
160{
161 struct net_device *dev = skb->dev;
162
163 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
164 dev->stats.rx_dropped++;
165 return NET_RX_DROP;
166 }
167
168 if (lapb_data_received(dev, skb) == LAPB_OK)
169 return NET_RX_SUCCESS;
170
171 dev->stats.rx_errors++;
172 dev_kfree_skb_any(skb);
173 return NET_RX_DROP;
174}
175
176
177static struct hdlc_proto proto = {
178 .open = x25_open,
179 .close = x25_close,
180 .ioctl = x25_ioctl,
181 .netif_rx = x25_rx,
182 .xmit = x25_xmit,
183 .module = THIS_MODULE,
184};
185
186
187static int x25_ioctl(struct net_device *dev, struct ifreq *ifr)
188{
189 hdlc_device *hdlc = dev_to_hdlc(dev);
190 int result;
191
192 switch (ifr->ifr_settings.type) {
193 case IF_GET_PROTO:
194 if (dev_to_hdlc(dev)->proto != &proto)
195 return -EINVAL;
196 ifr->ifr_settings.type = IF_PROTO_X25;
197 return 0; /* return protocol only, no settable parameters */
198
199 case IF_PROTO_X25:
200 if (!capable(CAP_NET_ADMIN))
201 return -EPERM;
202
203 if (dev->flags & IFF_UP)
204 return -EBUSY;
205
206 result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
207 if (result)
208 return result;
209
210 if ((result = attach_hdlc_protocol(dev, &proto, 0)))
211 return result;
212 dev->type = ARPHRD_X25;
213 call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
214 netif_dormant_off(dev);
215 return 0;
216 }
217
218 return -EINVAL;
219}
220
221
222static int __init mod_init(void)
223{
224 register_hdlc_protocol(&proto);
225 return 0;
226}
227
228
229
230static void __exit mod_exit(void)
231{
232 unregister_hdlc_protocol(&proto);
233}
234
235
236module_init(mod_init);
237module_exit(mod_exit);
238
239MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
240MODULE_DESCRIPTION("X.25 protocol support for generic HDLC");
241MODULE_LICENSE("GPL v2");